An operation to
remove the cancer and some normal tissue around it, but not
the breast itself. Some lymph nodes under the arm may be
removed for biopsy. Part of the chest wall lining may also
be removed if the cancer is near it. Also called breast-sparing surgery, lumpectomy, partial mastectomy, quadrantectomy, and segmental mastectomy.

Breast-conserving surgery. The tumor and some normal tissue around it are removed, but not the breast itself. Some lymph nodes under the arm may be removed. Part of the chest wall lining may also be removed if the cancer is near it.